American Standard Gas Furnace

Hi I purchased a used propane furnace. I hooked it up to test it and the chimney fan came on but not heat. While checking things I shorted the limit sw. to ground now the chimney fan wonít start. I donít see a fuse anywhere. The red light is blinking steady on the control panel. Did I possibly blow the low volt transformer?

Yes the red light blinks on off on off and not blinking codes. The board in my furnace does not have any fuse I can see. The furnace was used with LP prior and the heat exchanger is OK. The unit was running prior to being removed.

In order for me to help you further..... I need a model number for that furnace. It's inside on the side wall near the burner. You could post the model number off the control board too.

I would have expected a fuse to blow... if there was one. A quick short usually won't hurt the transformer. You could check the sensor you shorted. There should be 24vac on both sides of it measured to ground. Normally if the limit circuit was open..... you'd get a dedicated fault for that. A bit of a mystery here.

if I jump out the t-stat the chimney fan works
and I now am getting a three blink code
(Pressure Sw.)
I am getting a 27vac at both sides of the limit
sw.
Most likely when I shorted the limit sw. I burnt up the t-star?
There is three wires on the pressure sw two yellow have 27vac and no voltage at the orange wire with the fan running. Hope this helps. Thanks

The pressure switch won't close without the proper vacuum on it. That requires the proper flue connected to the furnace. On a call for heat..... just as the draft inducer starts..... you can short the pressure switch and see if the furnace continues with the ignition cycle.

Yes it will continue and the ign. glow l comes on but propane valve is not opening. I currently have it hooked up to a propane tank with a gas grill regular to test unit prior paying to have it installed?